<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        #context{
            width:500px;
            height:320px;
            margin:150px auto;
            position:relative;
        }
        #x-coordinate,#y-coordinate{
            position:absolute;
            left:0;
            background-color:#0000FF;
            z-index:1000;
        }
        #x-coordinate{
            width:500px;
            height:1px;
            top:160px;
        }
        #x-arrow,#y-arrow{
            width:0px;
            height:0px;
            border:5px solid transparent;
            position:absolute;
        }
        #x-arrow{
            border-left-color:#0000FF;
            right:-5px;
            top:-5px;
        }
        #y-arrow{
            border-bottom-color:#0000FF;
            left:-5px;
            top:-5px;
        }
        #y-coordinate{
            width:1px;
            height:320px;
            top:0;
        }
        .metaDiv{
            width:1px;
            height:240px;
            border-top:2px solid #0000FF;
        }
    </style>
</head>
<body>
<div id="context">
    <div id="x-coordinate">
        <div id="x-arrow"></div>
    </div>
    <div id="y-coordinate">
        <div id="y-arrow"></div>
    </div>
</div>
</body>
<script>
  var metaRadian = (Math.PI * 2) / 450
  var amplitude = 120
  var metaDivs = ''
  var context = document.getElementById('context')
  for (var i = 0, len = 450; i < len; i++) {
    var top_offset = 160 - Math.ceil(2 * i)
    metaDivs += "<div class='metaDiv' style='position:absolute;left:" + i + 'px;top:' + top_offset + "px'></div>"
  }
  context.innerHTML += metaDivs
</script>
</html>
